Flushing compositions



Patented May 18, 1954 FLUSHING COIVLP OSITIONS Oliver L. Brandes, Gibsonia, and Charles B. Pattinson, Jr., Oakmont, Pa, assignors to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware No Drawing. Application November 16, 1951, Serial No. 256,835

6 Claims.

This invention relates to improved flushing compositions for use in an internal combustion engine.

Flushing compositions are used in the crankcase of an internal combustion engine to remove gum, lacquer, and carbonaceous deposits from cylinder Walls, piston rings, and grooves, oil lines, bearings, the oil pump screen, the crank shaft, and the Walls of the crankcase.

Various flushing compositions have heretofore been disclosed for removing the undesirable deposits from an engine, but the prior compositions have not been entirely satisfactory for one or more reasons. Some of the prior compositions have exhibited good solvent properties but they have not had sufficient lubricating qualities to insure safe operations of an engine during the flushing period. Other compositions have possessed good lubricating characteristics, but they have been inefficient cleansers. Still other compositions have had good lubricating characteristics combined with moderately good cleansing properties, but these compositions have not been generally accepted because of their tendency to stratify during storage. Flushing compositions containing halogenated hydrocarbons have been widely used because the halogenated hydrocarbons are excellent solvents. The compositions containing halogenated hydrocarbons, however,

have certain drawbacks in that many of these compositions give offensive odors from the exlubricating characteristics and resistance against stratification during the normal handling, transportation, and storage of these compositions. The compositions of the present invention have a further desirable property in that when they are used, the odor of the exhaust gas is improved over the odor of the gas obtained when a halogencontaining flushing composition is used. The compositions of the invention are suitable for use not only in automotive engines but also in diesel and aircraft engines.

The improved flushing compositions of this invention consist essentially of a homogeneous mixture of isopropylphenol, lubricating oil, a watersoluble metallic soap, and water.

The isopropylphenol is believed to function as a solvent for removing the binder between the hard carbonaceous particles as well as for removing these particles from the metal surfaces. In preparing the flushing compositions of this invent-ion, we can use either isopropylphenol or a crude isopropylphenol mixture such as a commercially available isopropylphenol mixture Which contains smaller amounts of other alkyl phenols and phenol. For instance, we have produced stable homogeneous flushing compositions by employing as the isopropylphenol constituent a commercially available isopropylphenol mixture which consisted of a mixture of normal and isoprop'yl phenols together with smaller amounts of phenol, ethyl phenols, normal and isobutyl phenols. and higher-boiling phenols. Therefore, hereinafter and in the appended claims when we refer to isopropylphenol, it should be understood that we intend to include isopropylphenol per se and crude isopropylphenol mixtures containing a substantial proportion of isopropylphenol. The amount of isopropylphenol employed comprises at least about 5 per cent by weight of the flushing composition. The maximum amount of isopropylphenol which can be used depends upon its compatibility with the other constituents. In general, to produce compositions which will not stratify, isopropylphenol whether it is substantially pure isopropylphenol or a crude mixture thereof, should constitute not more than about per cent by weight of the flushing composition.

Lubricating oil is used to impart lubricity to the flushing composition and to give it the desired viscosity. Naturally the more viscous oils produce flushing compositions of higher viscosity. The lubricating oil may be derived from a paraffinic, naphthenic, or mixed base crude, or the oil may be a synthetic oil having a viscosity within the range of a mineral oil of lubricating grade. If desired, a blend of oils of suitable viscosity may be employed instead of a single oil, by means of which any desired viscosity within the range of about to 3500 SUS at 100 F. may be secured. The amount of the oil employed constitutes from about 10 per cent to about 60 per cent by weight of the total composition.

The water-soluble metallic soap aids in keeping the particles of sludge and carbonaceous ma terials in suspension after they have been removed from the engine parts. The soaps employed are those derived from the fatty acids, such as the soda soap or the potash soap of oleic acid, palmitic acid, linolinic acid, capric acid, linoleic acid, and mixtures thereof. The water content of the soap may comprise about 20 to about 50 per cent by Weight of the soap. While substantially moisture-free soaps can be used in preparing the compositions of the invention,

soaps containing at least about 30 to 40 per cent by weight of water are easier to blend with the other constituents. The soap constitutes about 5 to about 40 per cent by weight of the flushing composition.

Depending upon the water content of the soap and the amount of the soap used, additional water may or may not be required. Based upon the total weight of the flushing composition, the water should be present in an amount between about 2 and about 30 per cent by weight. The water is believed to function as an activator for the soap and apparently enables the soap to perform cleaning functions as well as those of a dispersant.

In isolated cases some difficulty may be encountered in preparing a mixture which is clear. For instance, it is possible to prepare two batches of flushing composition from the same ingredients under identical blending procedures and obtain one batch which is clear and one which is cloudy. The reason for this inconsistency has not been determined. However, we have found that this difficulty can be overcome and that a clear, homogeneous mixture can be obtained when this situation arises by adding a small amount of an emulsifier to the composition. The emulsifier used can be a commercially available emulsiier such as sorbitan monooleate, diethanolamine, triethanolamine, higher alkanol amines, diethylene glycol, and esters thereof, and the like. In general, when an emulsifying agent is employed it is added in an amount between about 0.1 and about 6.0 per cent based on the weight of the total composition. In any case, an amount suiiicient to suppress phase separation and to produce a clear, homogeneous mixture is employed.

In compositions of the type disclosed herein it is sometimes desirable to employ one or more of the so-called additive agents including oiliness and extreme pressure agents, viscosity index improvers, pour point depressants, foam inhibitors, and corrosion and oxidation inhibitors. Corrosion inhibitors are particularly desirable in flushing compositions used for the cleansing of aluminum pistons and corrodible alloy bearings, such as copper-lead, cadmium-silver, and cadmium-nickel. bearings. Corrosion inhibitors are also desirable in flushing compositions used in aircraft engines where lead-indium, high-lead babbitt, and other types of babbitt are frequently employed. The prevention of corrosion is also important in Diesel engines because the minute orifices in the fuel injectors are easily plugged if they become corroded. In instances where corrosion is likely to occur, we may add an inhibitor in an amount suiiicient to substantially inhibit corrosion of metal parts in contact with the flushing composition. in general, an amount between about 0.1 and about 2.0 per cent based upon the total weight of the flushing composition is sufficient. Among the corrosion inhibitors suitable for the purpose of our invention are dibenzyl disulfide, alkyl phenyl sulfides, alkyl phosphites, allraryl phosphites, sulfurized terpenes, sulfurized diisobutylene, and the like.

In compounding the compositions of the present invention, various blending procedures may be used either at room temperature or at an elevated temperature. In accordance with one embodiment, the soap can first be heated and then mixed with the other ingredients in a suitable mixing device. If an additive agent is employed, it may be incorporated in the oil be- Percent by Weight Constituents Maximum Minimum Added water l2 0 Water-soluble metallic soap 40 5 Lubricating oil .l 60 10 lsopiopylphenol 60 5 Em sitier 6 0 Corrosion inhibitor 2 O Specific examples of flushing compositions within the scope of our invention are as follows:

Composition, percent by weight A B Added water 4 4 Potash soap (35% water) 37 30 Lubricating oil (1900 SUV 1 lcxas 011)." 22 25 Isopropylphcuol mixture 40% isopropylphcnol). 35 40 Triethanolaminc l Sulfurized diisobutylene l l The physical properties of the above flushing compositions are approximately as follows:

Composition Gravity, API 9. 6 11.8 Viscosity, SUS:

at 100 204 176 at 210 F 48. 0 44. 5 Viscosity Index. 114 91 or, NPA 5- 5+ Pour Point, F -20 45 Flash Point, COO, F above 212 above 210 Each of the above compositions was clear when prepared. When samples of the above flushing compositions were stored in glass bottles placed in the sunlight, the compositions remained clear after standing for two weeks. Other samples stored at 32 F. for two weeks also remained clear.

in order to determine the effectiveness of the flushing compositions of the present invention for removing gum, lacquer, and carbonaceous deposits from an internal combustion engine, the following flushing procedure is employed. The used lubrieating oil is drained from the crankcase, the engine is then torn down, and examined for gum, lacquer, and other carbonaceous deposits. After determining the condition of the engine, it is reassembled, the crankcase is filled to approximately its normal capacity with an engine flushing composition, or if desired, the crankcase may be filled to approximately twice it normal capacity with the flushing composition. In most cases, however, it is satisfactory to the flushing composition in an amount equal to the normal crankcase capacity. The engine is then started and operated at about 900 R. P. M. with no load, for a period of about 90 minutes. The crankcase temperature obtained during this period preferably should not exceed about F. At the end of the 90-minute period the engine is stopped and the crankcase drained. The above procedure is then repeated using a light mineral lubricating oil for a period of about to minutes to remove the flushing composition held up in the engine and also to aid in draining from the engine, any remaining deposits which have been loosened by the flushing composition. The engine is then torn down and examined to determine the cleansing qualities of the flushing composition.

In order to illustrate the advantageou results obtained when a flushing composition of our invention is employed to remove gum, lacquer, and carbonaceous deposits from an internal combustion engine, the engine of a 1941 Chevrolet, having been driven approximately 60,000 miles, was

subjected to the above-described cleansing proce dure. The flushing composition employed was composition A set forth hereinabove. On disassembly of the engine prior to the start of the cleansing operation, the oil rings were noted to be about 90 per cent plugged with medium hard carbon; the oil screen was 100 per cent plugged with heavy soft gummy sludge; the crankcase oil pan contained heavy varnish with 4; inch winter sludge in the lower level; the piston skirts contained a medium to heavy varnish; the compression rings contained a heavy hard carbon; the connecting rods contained a medium varnish; the cylinder walls, the crank shaft and the bearings contained a light varnish; the push rod side of the block contained a medium soft sludge. After the cleansing operation was completed, the oil rings were found to be 100 per cent clean; the oil screen was about 85 to 90 per cent clean in the contact area; the crankcase oil pan was clean except for a small amount of sludge which remained in the lower level; the piston skirts, the compression rings, the connecting rods, the cylinder walls, the crank shaft, the bearings, and the push rod side of the block were clean. In further tests of other compositions within the scope of our invention on other makes and types of engines using a procedure similar to that described above, equally effective engine cleaning was obtained.

While our invention is described above with reference to various specific embodiments, it will be understood that the invention is not limited to such embodiments and may be variously practiced within the scope of the claims hereinafter made.

We claim:

1. A flushing composition consisting essentially of a homogeneous mixture of about 5 to about 60 per cent by weight of isopropylphenol; about 10 to about 60 per cent by weight of a mineral lubricating oil; about 5 to about 40 per cent by weight of a water-soluble metallic soap of a fatty acid, said soap containing about 20 to about 60 per cent by weight of water; and water in an amount sufficient to produce a flushing composition having a total water content between about 2 and about 30 per cent by weight.

2. A flushing composition consisting essentially of a homogeneous mixture of about 5 to about 60 per cent by weight of isopropylphenol; about 10 to about 60 per cent by weight of a mineral lubricating oil; about 5 to about 40 per cent by weight of a water-soluble metallic soap of a fatty acid, said soap containing about 20 to about 60 per cent by weight of water; an ethanolamine selected from the class consisting of diethanolamine and triethanolamine in an amount sufiicient to suppress phase separation; and water in an amount sufiicient to produce a flushing composition having a total water content between about 2 and about 30 per cent by weight.

3. A flushing composition consisting essentially of a homogeneous mixture of about 5 to about 60 per cent by weight of isopropylphenol; about 10 to about 60 per cent by weight of a mineral lubricating oil; about 5 to about 40 per cent by weight of a water-soluble metallic soap of a fatty acid, said soap containing about 20 to about 60 per cent by weight of water; a corrosion inhibitor in an amount sufficient to substantially inhibit corrosion of metal parts in contact with the flushing composition; and water in an amount sufiicient to produce a flushing composition having a total water content between about 2 and about 30 per cent by weight.

4. A flushing composition consisting essentially of a homogeneous mixture of about 5 to about 60 per cent by weight of isopropylphenol; about 10 to about 60 per cent by weight of a mineral lubricating oil; about 5 to about 40 per cent by weight of a water-soluble metallic soap of a fatty acid, said soap containing about 20 to about 60 per cent by weight of water; about 0.1 to about 6.0 per cent by weight of an ethanolamine selected from the class consisting of diethanolamine and triethanolamine; about 0.1 to about 2.0 per cent by weight of a corrosion inhibitor; and water in an amount sufficient to produce a flushing composition having a total water content between about 2 and about 30 per cent by weight.

5. A flushing composition consisting of a homogeneous mixture of about 35 per cent by weight of a commercial isopropylphenol, about 22 per cent by weight of a mineral lubricating oil, about 37 per cent by weight of a potash soap containing about 35 per cent by weight of water, about 4 per cent by weight of water, about 1 per cent by weight of triethanolamine, and about 1 per cent by weight of sulfurized diisobutylene.

6. A flushing composition consisting of a, homogeneous mixture of about 40 per cent by weight of a commercial isopropylphenol, about per cent by weight of a mineral lubricating oil, about per cent by weight of a potash soap containing about per cent by weight of water, about 4 per cent by weight of water, and about 1 per cent by weight of sulfurized diisobutylene.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,128,685 Yates Aug. 30, 1938 2,312,750 Cohen Mar. 2, 1943 2,355,591 Fla-xman Aug. 8, 1944 2,469,284 White May 3, 1949 OTHER REFERENCES Condensed Chemical Dictionary, 4th ed. (1950), page 3'73. 

1. A FLUSHING COMPOSITION CONSISTING ESSENTIALLY OF A HOMOGENEOUS MIXTURE OF ABOUT 5 TO ABOUT 60 PER CENT BY WEIGHT OF ISOPROPYLPHENOL; ABOUT 10 TO ABOUT 60 PER CENT BY WEIGHT OF A MINERAL LUBRICATING OIL; ABOUT 5 TO ABOUT 40 PER CENT BY WEIGHT OF A WATER-SOLUBLE METALLIC SOAP OF A FATTY ACID, SAID SOAP CONTAINING ABOUT 20 TO ABOUT 60 PER CENT BY WEIGHT OF WATER; AND WATER IN AN AMOUNT SUFFICIENT TO PRODUCE A FLUSHING COMPOSITION HAVING A TOTAL WATER CONTENT BETWEEN ABOUT 2 AND ABOUT 30 PER CENT BY WEIGHT. 